Telephonic transmitter



(No Model.) 2 Sheets-Sheet 2. S. E. BEEDY.

TELEPHONIG TRANSMITTER.

Patented out. 27, 1885.

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SETH EL A BEEDY, OF FARMINGTON, MAINE.

TELEPHONIC TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 329,001, dated October 27, 1885.

Application filed August 1, 1884.

To all whom it may concern:

Be it known that I, SETH E. BEEDY, a citizen of the United States, residing at Farmington, in the county of Franklin and State of Maine, haveinvented new and useful Improvements in Telephonic Transmitters, of which the following is a specification.

My invention relates to that class of telephonic transmitters adapted to alter, change,

or modify the normal condition of a current by interposing in its circuit and controlling. contacts therefor of low conductive capacity, so that it is rendered capable of transmitting articulate speech.

Its object is to provide a transmitter of simple and cheap construction, yet reliable in operation, easily affected by the vibrations of its diaphragm, and capable of being so affected even by the most delicate vibrations, easy of adjustment, and not liable to lose its adjustmentor get out of order. In accomplishing these results a diaphragm is mounted in any suitable containing case or box, constructed with a sound-receiving chamber in front of .the diaphragm and a mouth-piece for condensing the sound-vibrations and throwing them into the sound-chamber and upon the diaphragm. This diaphragm may be of any suitable material, but for delicacy of operation I prefer a rather large diaphragm made of thin wood, preferably such as is used for soundingboards in musical instruments. When such is used, it is well, in addition to its regular varnishing, to coat the surface or that part of the surface exposed directly to influence of the voice, with foil or foil-paper, in order the better to guard against the effect of any dampness which may be thrown thereon from the mouth of the talker. To the rear of this diaphragm is attached a carbon rod, or any low conductor, forming one electrode of the circuit.

In a frame attached to or supported from the case is pivoted a carbon cylinder adapted to take upon the rod and form the other electrode of the circuit. This frame is provided with means of adjustment so that the firmness of the contact of the roller electrode upon the rod electrode may be varied and regulated.

By using the roller electrode the slightest vibrations of the diaphragm cause the roller Serial No. 139,409. (No model.)

such roller-contacts may be used, for instance.

two or more disposed on one side of the carbon .rod and impinging thereon, or two may be used, one upon each side thereof. When the carbon rod is round, it is well to have 1t slightly flattened along the line of contact of the roller, so as to afford a better contact-sun face therefor.

The circuit thus controlled may be the main-line circuit itself or it may be the primary circuit of an inductorium whose secondary is connected to the main line. The arrangement thus generally set out may be better understood by reference to the drawings, in which- Figure 1 is a plan view of the transmitting apparatus; Fig. 2, a sectional view thereof, while Figs. 3 and 4 are side views of transmitters, each having several contact-rollers.

13 is the box or casing for containing the devices and within .which is located the diaphragm 1, which is here shown as made of a thin piece of suitable wood. Between the front of the diaphragm and the front 17 of the box, an air or sound chamber, 14, is formed for distributing the. vibrations over the diaphragm. A mouth-piece, 15, is secured to the front 17 ,in order that the-sound-vibrations may be more readily concentrated and thrown into the chamber and upon the diaphragm. In this case where wood is used as the material of the diaphragm, I prefer to place thereon, at least on that portion beneath the end of the mouth-piece, a cover of metal foil or foil paper, 16, guarding the Wood against any dampness from the voice of the talker. If desired, the entire surface of the diaphragm may be so covered and protected.

Upon the back of the diaphragm and projecting at right angles therefrom is secured the carbon rod 3, of any desired shape in crosssection, but here shown as round. It may be secured to the diaphragm by a metallic socket, 2, fastened thereto. 7

A carbon roller, 4, is journaled between the arms 5, so as to be capable of free rotation between the arms. The cross-piece uniting these arms is attached to an arm,6,which is pivoted at the point 8 in supports 9, attached to or springing from the case 13. These parts are so a'rranged relatively to each other that the roller 4 shall normally impinge upon the rod 3. At its outer end the arm 6 is provided with means for adjusting and controlling the degree of impingement, these means being here typified by the weight 7, adapted to be moved there along and then secured at the desired point.

The rod 3 forms one electrode forthe circuit of the battery whose current is to be controlled or modified, while the roller 4 forms the other. The circuit of this battery may be the mainline circuit, or it may be as shown in the drawings, where from one pole of the battery B a connection is made to 2, the circuit thence leading via 3 4 5 6 to the primary of inductorium 10 and thence to the other pole of the battery, the secondary of 10 being connected to the metallic or metallic and earth circuit 11 12. When, as in this case, the rod 3 is circular, it should be slightly flattened, as shown in Fig. 1, along the line of contact of 4 therewith, in order to give greater area of contact.

As 4 is capable of rolling under the movement of 3, much less force is needed to cause such movement, hence 3 and 4 can mutually respond and move even under the most delicate vibrations of 1, adding thereby largely to the efficiency of the transmitter. In addition the rotation of 4 insures an evenness of wear over the line of contact of its entire pe-v riphery, avoiding irregular wearing away at anyparticular point. If such rotation should not occur under theaction of the carbon rod thereon, it is easy, occasionally, or as the rotary electrode shows sign of wear, to turn the rolling electrode by hand.

Instead of one roller being used several may be used in the same circuit. For instance, in

Fig. 3, two rollers 4 are used, one on each side tacts of low conductive capacity.

I make no claim herein to the peculiar diaphragm used-that is, one formed of wood having that part beneath the mouth-piece covered with foil or foil-paperas such a diaphragm will form the subject-matter of a separate ap plication for patent;

I am aware that it has been proposed to support a carbon roller upon a diaphragm and form the other electrode by a flat metallic spring whose free end is beveled or inclined, the bevel contacting the roller. Such construction I do not therefore claim.

Having thus described my invention, what I claim is 1. In a telephonic transmitter, the combination of a diaphragm, a carbon rod secured thereto and moving therewith, one or more contact-rollers adapted to impinge thereon, and one or more swinging or pivoted frames, one for each contact-roller, in which the contactrollers are journaled, substantially as described.

2. In a telephonic transmitter, the combination of a diaphragm, a carbon rod attached thereto, one or more contact-rollers, each j ournaled in a swinging frame and adapted to impinge on the rod, and means for adjusting the degree of impingement or contact, substantially as described.

3. In a telephonic transmitter, the combination of a diaphragm, a carbon rod attached thereto, one or more contact-rollers, 4, each journaled in a frame, 5, the frame 5, and arm 6, pivoted in standard 9, and the adjustable weight 7 thereon, substantially as described.

4. In a telephonic transmitter, the combination of a diaphragm, a circular carbon rod attached thereto and moving therewith, and one or more contact-rollers pivotally journaled and adapted to impinge on the carbon rod, the circular carbon rod being slightly flattened along the line of impingement or contact, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

SETH ELA BEEDY.

Witnesses:

JAMES L. NoRRis, Jos. L. CooMBs. 

